1. Field of Invention
The present invention relates to a wrench and, more particularly, to a well coated wrench.
2. Related Prior Art
A wrench is generally made of metal for excellent rigidity. However, a user might get an electric shock while operating a metal wrench.
To avoid an electric shock, handles of some metal wrenches are coated with an isolative material such as rubber and plastics. However, a user might touch another portion of a metal wrench with a rubber or plastics-coated handle and get an electric shock.
To effectively avoid an electric shock, a well coated wrench is devised referring to FIG. 1. The well coated wrench is a one-way wrench. The one-way wrench includes a shank, a handle formed at an end of the shank, and a head formed at an opposite end of the shank. The shank, the handle and the head are made of metal in one piece. The shank, the handle and the head are coated with an isolative coating 1 of rubber or plastics. A one-way mechanism is substantially located in a tunnel 2 defined in the head. The one-way mechanism includes a tongue 3 located outside the head. The tongue 3 is also made of metal. The tongue 3 is not coated with any isolative material for precise size and excellent rigidity. A detent 5 is attached to the tongue 3. The detent 5 includes a first portion located in the tongue 3 and a second portion that is normally located outside the tongue 5. A button 4 is operable to release the detent 5 so that the second portion of the detent 5 can be moved into the tongue 3. The coating 1 includes an annular ridge 8 around the tunnel 2.
The well coated wrench is tested in an isolation-testing machine before it is made available on the market. The well coated wrench is buried in steel balls 6 after the tongue 3 is located in an isolative cup 7. It is determined whether there is any current between the steel balls 6 and the one-way mechanism. The annular ridge 8 is expected to prevent the steel balls 6 from entering the tunnel 2 and reaching the one-way mechanism. However, the steel balls 6 could get really close to the one-way mechanism when the button 4 is not pushed because an external diameter of the annular ridge 8 is smaller than an internal diameter of the button 4. Therefore, the well coated wrench could fail the test by mistake.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.